Skip to main content
Matthew Grimshaw
All Posts By

Matthew Grimshaw

Matt Grimshaw — known as Coach Grimmy — is the founder of SISU Fitness, a HYROX-affiliated gym coaching athletes from first-timers to world podium contenders. He blends functional fitness science with SISU grit to help you train, race, and perform at your best.

Group of athletes cheering each other through the last few wall balls
The SISU Mentality: How to Stay in the Fight When It HurtsArticlesHabits, Tech & MindsetHYROX Training

The SISU Mentality: How to Stay in the Fight When It Hurts

Pain is guaranteed in HYROX quitting is optional. The SISU mentality is about finding strength in struggle and learning to…
Matthew GrimshawMatthew GrimshawOctober 8, 20253 min
Athletes performing sled pushes, carries, and burpees in a gritty gym — chalk in the air, focused intensity, and a coach motivating in the background
Why Functional Fitness Beats Fancy ProgrammingArticlesHYROX TrainingStrength & Conditioning

Why Functional Fitness Beats Fancy Programming

You don’t need fancy programming or exotic movements to get strong, fit, and race-ready. You need fundamentals done well —…
Matthew GrimshawMatthew GrimshawOctober 8, 20253 min
Athlete mid-HYROX race, grit and focus on their face, pushing a sled across the floor surrounded by cheering crowd — captured under bright competition lighting with energy and intensity
How to Pace Every HYROX Station (and Avoid Blowing Up Mid-Race)ArticlesHYROX TrainingRace Strategy

How to Pace Every HYROX Station (and Avoid Blowing Up Mid-Race)

Most HYROX athletes don’t lose their race on the sled push — they lose it on the run before it.…
Matthew GrimshawMatthew GrimshawOctober 8, 20253 min
Athlete standing at the HYROX start line, nervous but focused, surrounded by competitors — bright lights, race banners, energy and anticipation in the air
From Couch to HYROX: Your Complete Beginner’s Guide to Race-Day SuccessArticlesHYROX Training

From Couch to HYROX: Your Complete Beginner’s Guide to Race-Day Success

HYROX can look intimidating — sleds, wall balls, running — but anyone can cross that finish line with the right…
Matthew GrimshawMatthew GrimshawOctober 1, 20253 min